remove blkdev_get as a public API

remove blkdev_get as a public API

[Christoph Hellwig]

Hi Jens,

this series removes blkdev_get as a public API, leaving it as just an
implementation detail of blkdev_get_by_path and blkdev_get_by_dev.  The
reason for that is that blkdev_get is a very confusing API that requires
a struct block_device to be fed in, but then actually consumes the
reference.  And it turns out just using the two above mentioned APIs
actually significantly simplifies the code as well.

Diffstat:
 block/genhd.c                   |   11 ++--
 block/ioctl.c                   |   13 ++---
 drivers/block/nbd.c             |    8 +--
 drivers/block/pktcdvd.c         |   92 +++++-----------------------------------
 drivers/block/zram/zram_drv.c   |    7 +--
 drivers/char/raw.c              |   51 ++++++++--------------
 drivers/ide/ide-gd.c            |    2 
 drivers/s390/block/dasd_genhd.c |   13 +----
 fs/block_dev.c                  |   12 ++---
 fs/ocfs2/cluster/heartbeat.c    |   28 ++++--------
 include/linux/blk_types.h       |    4 -
 include/linux/blkdev.h          |    1 
 include/linux/genhd.h           |    2 
 include/linux/suspend.h         |    4 -
 include/linux/swap.h            |    3 -
 kernel/power/swap.c             |   21 +++------
 kernel/power/user.c             |   26 +++--------
 mm/swapfile.c                   |   45 ++++++++++---------
 18 files changed, 119 insertions(+), 224 deletions(-)

[PATCH 01/14] block: move the NEED_PART_SCAN flag to struct gendisk

[Christoph Hellwig]

We can only scan for partitions on the whole disk, so move the flag
from struct block_device to struct gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c             | 4 ++--
 drivers/block/nbd.c       | 8 ++++----
 drivers/ide/ide-gd.c      | 2 +-
 fs/block_dev.c            | 7 +++----
 include/linux/blk_types.h | 4 +---
 include/linux/genhd.h     | 2 ++
 6 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 9d060e79eb31d8..7b56203c90a303 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -731,7 +731,7 @@ static void register_disk(struct device *parent, struct gendisk *disk,
 	if (!bdev)
 		goto exit;
 
-	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	set_bit(GD_NEED_PART_SCAN, &disk->state);
 	err = blkdev_get(bdev, FMODE_READ, NULL);
 	if (err < 0)
 		goto exit;
@@ -2112,7 +2112,7 @@ bool bdev_check_media_change(struct block_device *bdev)
 	if (__invalidate_device(bdev, true))
 		pr_warn("VFS: busy inodes on changed media %s\n",
 			bdev->bd_disk->disk_name);
-	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	return true;
 }
 EXPORT_SYMBOL(bdev_check_media_change);
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 15eed210feeff4..2dca0aab0a9a25 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -315,7 +315,7 @@ static void nbd_size_update(struct nbd_device *nbd)
 			bd_set_nr_sectors(bdev, nr_sectors);
 			set_blocksize(bdev, config->blksize);
 		} else
-			set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+			set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 		bdput(bdev);
 	}
 	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
@@ -1322,7 +1322,7 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b
 		return ret;
 
 	if (max_part)
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 	mutex_unlock(&nbd->config_lock);
 	ret = wait_event_interruptible(config->recv_wq,
 					 atomic_read(&config->recv_threads) == 0);
@@ -1500,9 +1500,9 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
 		refcount_set(&nbd->config_refs, 1);
 		refcount_inc(&nbd->refs);
 		mutex_unlock(&nbd->config_lock);
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	} else if (nbd_disconnected(nbd->config)) {
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	}
 out:
 	mutex_unlock(&nbd_index_mutex);
diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c
index 661e2aa9c96784..e2b6c82586ce8b 100644
--- a/drivers/ide/ide-gd.c
+++ b/drivers/ide/ide-gd.c
@@ -230,7 +230,7 @@ static int ide_gd_open(struct block_device *bdev, fmode_t mode)
 				bdev->bd_disk->disk_name);
 		drive->disk_ops->get_capacity(drive);
 		set_capacity(disk, ide_gd_capacity(drive));
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &disk->state);
 	} else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) {
 		ret = -EBUSY;
 		goto out_put_idkp;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0b34955b9e360f..1a9325f4315769 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -910,7 +910,6 @@ struct block_device *bdget(dev_t dev)
 		bdev->bd_super = NULL;
 		bdev->bd_inode = inode;
 		bdev->bd_part_count = 0;
-		bdev->bd_flags = 0;
 		inode->i_mode = S_IFBLK;
 		inode->i_rdev = dev;
 		inode->i_bdev = bdev;
@@ -1385,7 +1384,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
 
 	lockdep_assert_held(&bdev->bd_mutex);
 
-	clear_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 
 rescan:
 	ret = blk_drop_partitions(bdev);
@@ -1509,7 +1508,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 			 * The latter is necessary to prevent ghost
 			 * partitions on a removed medium.
 			 */
-			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
+			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
 			    (!ret || ret == -ENOMEDIUM))
 				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
 
@@ -1539,7 +1538,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 			if (bdev->bd_disk->fops->open)
 				ret = bdev->bd_disk->fops->open(bdev, mode);
 			/* the same as first opener case, read comment there */
-			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
+			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
 			    (!ret || ret == -ENOMEDIUM))
 				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
 			if (ret)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 6ffa783e16335e..eb20e28184ab19 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -19,8 +19,6 @@ struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
 struct bio_crypt_ctx;
 
-#define BDEV_NEED_PART_SCAN		0
-
 struct block_device {
 	dev_t			bd_dev;
 	int			bd_openers;
@@ -39,7 +37,7 @@ struct block_device {
 	struct hd_struct *	bd_part;
 	/* number of times partitions within this device have been opened. */
 	unsigned		bd_part_count;
-	unsigned long		bd_flags;
+
 	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */
 	struct gendisk *	bd_disk;
 	struct backing_dev_info *bd_bdi;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 1c97cf84f011a7..38f23d75701379 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -191,6 +191,8 @@ struct gendisk {
 	void *private_data;
 
 	int flags;
+	unsigned long state;
+#define GD_NEED_PART_SCAN		0
 	struct rw_semaphore lookup_sem;
 	struct kobject *slave_dir;
 
-- 
2.28.0

[PATCH 02/14] block: switch register_disk to use blkdev_get_by_dev

[Christoph Hellwig]

Use blkdev_get_by_dev instead of open coding it using bdget_disk +
blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 7b56203c90a303..f778716fac6cde 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -732,10 +732,9 @@ static void register_disk(struct device *parent, struct gendisk *disk,
 		goto exit;
 
 	set_bit(GD_NEED_PART_SCAN, &disk->state);
-	err = blkdev_get(bdev, FMODE_READ, NULL);
-	if (err < 0)
-		goto exit;
-	blkdev_put(bdev, FMODE_READ);
+	bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
+	if (!IS_ERR(bdev))
+		blkdev_put(bdev, FMODE_READ);
 
 exit:
 	/* announce disk after possible partitions are created */
-- 
2.28.0

[PATCH 03/14] block: cleanup blkdev_bszset

[Christoph Hellwig]

Use blkdev_get_by_dev instead of bdgrab + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/ioctl.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index ae74d0409afab9..06262c28f0c6c1 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -478,15 +478,14 @@ static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
 	if (get_user(n, argp))
 		return -EFAULT;
 
-	if (!(mode & FMODE_EXCL)) {
-		bdgrab(bdev);
-		if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
-			return -EBUSY;
-	}
+	if (mode & FMODE_EXCL)
+		return set_blocksize(bdev, n);
 
+	if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev)))
+		return -EBUSY;
 	ret = set_blocksize(bdev, n);
-	if (!(mode & FMODE_EXCL))
-		blkdev_put(bdev, mode | FMODE_EXCL);
+	blkdev_put(bdev, mode | FMODE_EXCL);
+
 	return ret;
 }
 
-- 
2.28.0

[PATCH 04/14] pktcdvd: remove the if 0'ed pkt_start_recovery function

[Christoph Hellwig]

Remove code which has been dead since the initial commit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/pktcdvd.c | 67 ++---------------------------------------
 1 file changed, 2 insertions(+), 65 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 17f2e6ff122314..bc870a5f15f77b 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1082,65 +1082,6 @@ static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *p
 	}
 }
 
-/*
- * recover a failed write, query for relocation if possible
- *
- * returns 1 if recovery is possible, or 0 if not
- *
- */
-static int pkt_start_recovery(struct packet_data *pkt)
-{
-	/*
-	 * FIXME. We need help from the file system to implement
-	 * recovery handling.
-	 */
-	return 0;
-#if 0
-	struct request *rq = pkt->rq;
-	struct pktcdvd_device *pd = rq->rq_disk->private_data;
-	struct block_device *pkt_bdev;
-	struct super_block *sb = NULL;
-	unsigned long old_block, new_block;
-	sector_t new_sector;
-
-	pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
-	if (pkt_bdev) {
-		sb = get_super(pkt_bdev);
-		bdput(pkt_bdev);
-	}
-
-	if (!sb)
-		return 0;
-
-	if (!sb->s_op->relocate_blocks)
-		goto out;
-
-	old_block = pkt->sector / (CD_FRAMESIZE >> 9);
-	if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
-		goto out;
-
-	new_sector = new_block * (CD_FRAMESIZE >> 9);
-	pkt->sector = new_sector;
-
-	bio_reset(pkt->bio);
-	bio_set_dev(pkt->bio, pd->bdev);
-	bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0);
-	pkt->bio->bi_iter.bi_sector = new_sector;
-	pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
-	pkt->bio->bi_vcnt = pkt->frames;
-
-	pkt->bio->bi_end_io = pkt_end_io_packet_write;
-	pkt->bio->bi_private = pkt;
-
-	drop_super(sb);
-	return 1;
-
-out:
-	drop_super(sb);
-	return 0;
-#endif
-}
-
 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
 {
 #if PACKET_DEBUG > 1
@@ -1357,12 +1298,8 @@ static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data
 			break;
 
 		case PACKET_RECOVERY_STATE:
-			if (pkt_start_recovery(pkt)) {
-				pkt_start_write(pd, pkt);
-			} else {
-				pkt_dbg(2, pd, "No recovery possible\n");
-				pkt_set_state(pkt, PACKET_FINISHED_STATE);
-			}
+			pkt_dbg(2, pd, "No recovery possible\n");
+			pkt_set_state(pkt, PACKET_FINISHED_STATE);
 			break;
 
 		case PACKET_FINISHED_STATE:
-- 
2.28.0

[PATCH 05/14] pktcdvd: use blkdev_get_by_dev instead of open coding it

[Christoph Hellwig]

Replace bdget + blkdev_get by blkdev_get_by_dev.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/pktcdvd.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index bc870a5f15f77b..467dbd06b7cdb1 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2110,16 +2110,18 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 	int ret;
 	long lba;
 	struct request_queue *q;
+	struct block_device *bdev;
 
 	/*
 	 * We need to re-open the cdrom device without O_NONBLOCK to be able
 	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
-	 * so bdget() can't fail.
+	 * so open should not fail.
 	 */
-	bdget(pd->bdev->bd_dev);
-	ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd);
-	if (ret)
+	bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd);
+	if (IS_ERR(bdev)) {
+		ret = PTR_ERR(bdev);
 		goto out;
+	}
 
 	ret = pkt_get_last_written(pd, &lba);
 	if (ret) {
@@ -2163,7 +2165,7 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 	return 0;
 
 out_putdev:
-	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
+	blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
 out:
 	return ret;
 }
@@ -2500,7 +2502,6 @@ static int pkt_seq_show(struct seq_file *m, void *p)
 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
 {
 	int i;
-	int ret = 0;
 	char b[BDEVNAME_SIZE];
 	struct block_device *bdev;
 
@@ -2523,12 +2524,9 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
 		}
 	}
 
-	bdev = bdget(dev);
-	if (!bdev)
-		return -ENOMEM;
-	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
-	if (ret)
-		return ret;
+	bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL);
+	if (IS_ERR(bdev))
+		return PTR_ERR(bdev);
 	if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
 		blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
 		return -EINVAL;
@@ -2546,7 +2544,6 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
 	pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
 	if (IS_ERR(pd->cdrw.thread)) {
 		pkt_err(pd, "can't start kernel thread\n");
-		ret = -ENOMEM;
 		goto out_mem;
 	}
 
@@ -2558,7 +2555,7 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
 	blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
 	/* This is safe: open() is still holding a reference. */
 	module_put(THIS_MODULE);
-	return ret;
+	return -ENOMEM;
 }
 
 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
-- 
2.28.0

[PATCH 06/14] zram: cleanup backing_dev_store

[Christoph Hellwig]

Use blkdev_get_by_dev instead of bdgrab + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/zram/zram_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index a356275605b104..91ccfe444525b4 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -491,9 +491,10 @@ static ssize_t backing_dev_store(struct device *dev,
 		goto out;
 	}
 
-	bdev = bdgrab(I_BDEV(inode));
-	err = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram);
-	if (err < 0) {
+	bdev = blkdev_get_by_dev(inode->i_rdev,
+			FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram);
+	if (IS_ERR(bdev)) {
+		err = PTR_ERR(bdev);
 		bdev = NULL;
 		goto out;
 	}
-- 
2.28.0

[PATCH 07/14] raw: don't keep unopened block device around

[Christoph Hellwig]

Turn binding into a normal dev_t as the struct block device doesn't
buy us anything and use blkdev_open_by_dev to actually open it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/char/raw.c | 51 +++++++++++++++++-----------------------------
 1 file changed, 19 insertions(+), 32 deletions(-)

diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index ccf5bd528642da..5d52a1f4738c76 100644
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -28,7 +28,8 @@
 #include <linux/uaccess.h>
 
 struct raw_device_data {
-	struct block_device *binding;
+	dev_t binding;
+	struct block_device *bdev;
 	int inuse;
 };
 
@@ -73,14 +74,15 @@ static int raw_open(struct inode *inode, struct file *filp)
 	/*
 	 * All we need to do on open is check that the device is bound.
 	 */
-	bdev = raw_devices[minor].binding;
 	err = -ENODEV;
-	if (!bdev)
+	if (!raw_devices[minor].binding)
 		goto out;
-	bdgrab(bdev);
-	err = blkdev_get(bdev, filp->f_mode | FMODE_EXCL, raw_open);
-	if (err)
+	bdev = blkdev_get_by_dev(raw_devices[minor].binding,
+				 filp->f_mode | FMODE_EXCL, raw_open);
+	if (IS_ERR(bdev)) {
+		err = PTR_ERR(bdev);
 		goto out;
+	}
 	err = set_blocksize(bdev, bdev_logical_block_size(bdev));
 	if (err)
 		goto out1;
@@ -90,6 +92,7 @@ static int raw_open(struct inode *inode, struct file *filp)
 		file_inode(filp)->i_mapping =
 			bdev->bd_inode->i_mapping;
 	filp->private_data = bdev;
+	raw_devices[minor].bdev = bdev;
 	mutex_unlock(&raw_mutex);
 	return 0;
 
@@ -110,7 +113,7 @@ static int raw_release(struct inode *inode, struct file *filp)
 	struct block_device *bdev;
 
 	mutex_lock(&raw_mutex);
-	bdev = raw_devices[minor].binding;
+	bdev = raw_devices[minor].bdev;
 	if (--raw_devices[minor].inuse == 0)
 		/* Here  inode->i_mapping == bdev->bd_inode->i_mapping  */
 		inode->i_mapping = &inode->i_data;
@@ -133,6 +136,7 @@ raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
 static int bind_set(int number, u64 major, u64 minor)
 {
 	dev_t dev = MKDEV(major, minor);
+	dev_t raw = MKDEV(RAW_MAJOR, number);
 	struct raw_device_data *rawdev;
 	int err = 0;
 
@@ -166,25 +170,17 @@ static int bind_set(int number, u64 major, u64 minor)
 		mutex_unlock(&raw_mutex);
 		return -EBUSY;
 	}
-	if (rawdev->binding) {
-		bdput(rawdev->binding);
+	if (rawdev->binding)
 		module_put(THIS_MODULE);
-	}
+
+	rawdev->binding = dev;
 	if (!dev) {
 		/* unbind */
-		rawdev->binding = NULL;
-		device_destroy(raw_class, MKDEV(RAW_MAJOR, number));
+		device_destroy(raw_class, raw);
 	} else {
-		rawdev->binding = bdget(dev);
-		if (rawdev->binding == NULL) {
-			err = -ENOMEM;
-		} else {
-			dev_t raw = MKDEV(RAW_MAJOR, number);
-			__module_get(THIS_MODULE);
-			device_destroy(raw_class, raw);
-			device_create(raw_class, NULL, raw, NULL,
-				      "raw%d", number);
-		}
+		__module_get(THIS_MODULE);
+		device_destroy(raw_class, raw);
+		device_create(raw_class, NULL, raw, NULL, "raw%d", number);
 	}
 	mutex_unlock(&raw_mutex);
 	return err;
@@ -192,18 +188,9 @@ static int bind_set(int number, u64 major, u64 minor)
 
 static int bind_get(int number, dev_t *dev)
 {
-	struct raw_device_data *rawdev;
-	struct block_device *bdev;
-
 	if (number <= 0 || number >= max_raw_minors)
 		return -EINVAL;
-
-	rawdev = &raw_devices[number];
-
-	mutex_lock(&raw_mutex);
-	bdev = rawdev->binding;
-	*dev = bdev ? bdev->bd_dev : 0;
-	mutex_unlock(&raw_mutex);
+	*dev = raw_devices[number].binding;
 	return 0;
 }
 
-- 
2.28.0

[PATCH 08/14] dasd: cleanup dasd_scan_partitions

[Christoph Hellwig]

Use blkdev_get_by_dev instead of bdget_disk + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/s390/block/dasd_genhd.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index af5b0ecb8f8923..70c09a46d22806 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -101,18 +101,11 @@ int dasd_scan_partitions(struct dasd_block *block)
 	struct block_device *bdev;
 	int rc;
 
-	bdev = bdget_disk(block->gdp, 0);
-	if (!bdev) {
-		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
-			      "scan partitions error, bdget returned NULL");
-		return -ENODEV;
-	}
-
-	rc = blkdev_get(bdev, FMODE_READ, NULL);
-	if (rc < 0) {
+	bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL);
+	if (IS_ERR(bdev)) {
 		DBF_DEV_EVENT(DBF_ERR, block->base,
 			      "scan partitions error, blkdev_get returned %d",
-			      rc);
+			      IS_ERR(bdev));
 		return -ENODEV;
 	}
 
-- 
2.28.0

[PATCH 09/14] ocfs2: cleanup o2hb_region_dev_store

[Christoph Hellwig]

Use blkdev_get_by_dev instead of igrab (aka open coded bdgrab) +
blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/ocfs2/cluster/heartbeat.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 89d13e0705fe7b..0179a73a3fa2c4 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1766,7 +1766,6 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
 	int sectsize;
 	char *p = (char *)page;
 	struct fd f;
-	struct inode *inode;
 	ssize_t ret = -EINVAL;
 	int live_threshold;
 
@@ -1793,20 +1792,16 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
 	    reg->hr_block_bytes == 0)
 		goto out2;
 
-	inode = igrab(f.file->f_mapping->host);
-	if (inode == NULL)
+	if (!S_ISBLK(f.file->f_mapping->host->i_mode))
 		goto out2;
 
-	if (!S_ISBLK(inode->i_mode))
-		goto out3;
-
-	reg->hr_bdev = I_BDEV(f.file->f_mapping->host);
-	ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL);
-	if (ret) {
+	reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev,
+					 FMODE_WRITE | FMODE_READ, NULL);
+	if (IS_ERR(reg->hr_bdev)) {
+		ret = PTR_ERR(reg->hr_bdev);
 		reg->hr_bdev = NULL;
-		goto out3;
+		goto out2;
 	}
-	inode = NULL;
 
 	bdevname(reg->hr_bdev, reg->hr_dev_name);
 
@@ -1909,16 +1904,13 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
 		       config_item_name(&reg->hr_item), reg->hr_dev_name);
 
 out3:
-	iput(inode);
+	if (ret < 0) {
+		blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE);
+		reg->hr_bdev = NULL;
+	}
 out2:
 	fdput(f);
 out:
-	if (ret < 0) {
-		if (reg->hr_bdev) {
-			blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
-			reg->hr_bdev = NULL;
-		}
-	}
 	return ret;
 }
 
-- 
2.28.0

[PATCH 10/14] mm: cleanup claim_swapfile

[Christoph Hellwig]

Use blkdev_get_by_dev instead of bdgrab + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/swapfile.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 12f59e641b5e29..7438c4affc75fa 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2920,10 +2920,10 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
 	int error;
 
 	if (S_ISBLK(inode->i_mode)) {
-		p->bdev = bdgrab(I_BDEV(inode));
-		error = blkdev_get(p->bdev,
+		p->bdev = blkdev_get_by_dev(inode->i_rdev,
 				   FMODE_READ | FMODE_WRITE | FMODE_EXCL, p);
-		if (error < 0) {
+		if (IS_ERR(p->bdev)) {
+			error = PTR_ERR(p->bdev);
 			p->bdev = NULL;
 			return error;
 		}
-- 
2.28.0

[PATCH 11/14] PM: rewrite is_hibernate_resume_dev to not require an inode

[Christoph Hellwig]

Just check the dev_t to help simplifying the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/block_dev.c          |  2 +-
 include/linux/suspend.h |  4 ++--
 kernel/power/user.c     | 12 ++++++------
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1a9325f4315769..2898d69be6b3e4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1885,7 +1885,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (bdev_read_only(I_BDEV(bd_inode)))
 		return -EPERM;
 
-	if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode))
+	if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
 		return -ETXTBSY;
 
 	if (!iov_iter_count(from))
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index cb9afad82a90c8..8af13ba60c7e45 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -473,9 +473,9 @@ static inline int hibernate_quiet_exec(int (*func)(void *data), void *data) {
 #endif /* CONFIG_HIBERNATION */
 
 #ifdef CONFIG_HIBERNATION_SNAPSHOT_DEV
-int is_hibernate_resume_dev(const struct inode *);
+int is_hibernate_resume_dev(dev_t dev);
 #else
-static inline int is_hibernate_resume_dev(const struct inode *i) { return 0; }
+static inline int is_hibernate_resume_dev(dev_t dev) { return 0; }
 #endif
 
 /* Hibernation and suspend events */
diff --git a/kernel/power/user.c b/kernel/power/user.c
index d5eedc2baa2a10..b5815685b944fe 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -35,12 +35,12 @@ static struct snapshot_data {
 	bool ready;
 	bool platform_support;
 	bool free_bitmaps;
-	struct inode *bd_inode;
+	dev_t dev;
 } snapshot_state;
 
-int is_hibernate_resume_dev(const struct inode *bd_inode)
+int is_hibernate_resume_dev(dev_t dev)
 {
-	return hibernation_available() && snapshot_state.bd_inode == bd_inode;
+	return hibernation_available() && snapshot_state.dev == dev;
 }
 
 static int snapshot_open(struct inode *inode, struct file *filp)
@@ -101,7 +101,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	data->frozen = false;
 	data->ready = false;
 	data->platform_support = false;
-	data->bd_inode = NULL;
+	data->dev = 0;
 
  Unlock:
 	unlock_system_sleep();
@@ -117,7 +117,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 
 	swsusp_free();
 	data = filp->private_data;
-	data->bd_inode = NULL;
+	data->dev = 0;
 	free_all_swap_pages(data->swap);
 	if (data->frozen) {
 		pm_restore_gfp_mask();
@@ -245,7 +245,7 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 	if (data->swap < 0)
 		return -ENODEV;
 
-	data->bd_inode = bdev->bd_inode;
+	data->dev = bdev->bd_dev;
 	bdput(bdev);
 	return 0;
 }
-- 
2.28.0

[PATCH 12/14] mm: split swap_type_of

[Christoph Hellwig]

swap_type_of is used for two entirely different purposes:

 (1) check what swap type a given device/offset corresponds to
 (2) find the first available swap device that can be written to

Mixing both in a single function creates an unreadable mess.  Create two
separate functions instead, and switch both to pass a dev_t instead of
a struct block_device to further simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/swap.h |  3 ++-
 kernel/power/swap.c  | 17 ++++++++---------
 kernel/power/user.c  | 16 ++++------------
 mm/swapfile.c        | 39 +++++++++++++++++++++------------------
 4 files changed, 35 insertions(+), 40 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 661046994db4b9..4340a7b6e7a1dc 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -467,7 +467,8 @@ extern int swapcache_prepare(swp_entry_t);
 extern void swap_free(swp_entry_t);
 extern void swapcache_free_entries(swp_entry_t *entries, int n);
 extern int free_swap_and_cache(swp_entry_t);
-extern int swap_type_of(dev_t, sector_t, struct block_device **);
+int swap_type_of(dev_t device, sector_t offset);
+int find_first_swap(dev_t *device);
 extern unsigned int count_swap_pages(int, int);
 extern sector_t map_swap_page(struct page *, struct block_device **);
 extern sector_t swapdev_block(int, pgoff_t);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 01e2858b5fe367..9d3ffbfe08dbf6 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -335,12 +335,17 @@ static int swsusp_swap_check(void)
 {
 	int res;
 
-	res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
-			&hib_resume_bdev);
+	if (swsusp_resume_device)
+		res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
+	else
+		res = find_first_swap(&swsusp_resume_device);
 	if (res < 0)
 		return res;
-
 	root_swap = res;
+
+	hib_resume_bdev = bdget(swsusp_resume_device);
+	if (!hib_resume_bdev)
+		return -ENOMEM;
 	res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 	if (res)
 		return res;
@@ -349,12 +354,6 @@ static int swsusp_swap_check(void)
 	if (res < 0)
 		blkdev_put(hib_resume_bdev, FMODE_WRITE);
 
-	/*
-	 * Update the resume device to the one actually used,
-	 * so the test_resume mode can use it in case it is
-	 * invoked from hibernate() to test the snapshot.
-	 */
-	swsusp_resume_device = hib_resume_bdev->bd_dev;
 	return res;
 }
 
diff --git a/kernel/power/user.c b/kernel/power/user.c
index b5815685b944fe..6510a8f7687f42 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -69,8 +69,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	memset(&data->handle, 0, sizeof(struct snapshot_handle));
 	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
 		/* Hibernating.  The image device should be accessible. */
-		data->swap = swsusp_resume_device ?
-			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
+		data->swap = swap_type_of(swsusp_resume_device, 0);
 		data->mode = O_RDONLY;
 		data->free_bitmaps = false;
 		error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
@@ -210,7 +209,6 @@ struct compat_resume_swap_area {
 static int snapshot_set_swap_area(struct snapshot_data *data,
 		void __user *argp)
 {
-	struct block_device *bdev;
 	sector_t offset;
 	dev_t swdev;
 
@@ -237,16 +235,10 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 	 * User space encodes device types as two-byte values,
 	 * so we need to recode them
 	 */
-	if (!swdev) {
-		data->swap = -1;
-		return -EINVAL;
-	}
-	data->swap = swap_type_of(swdev, offset, &bdev);
+	data->swap = swap_type_of(swdev, offset);
 	if (data->swap < 0)
-		return -ENODEV;
-
-	data->dev = bdev->bd_dev;
-	bdput(bdev);
+		return swdev ? -ENODEV : -EINVAL;
+	data->dev = swdev;
 	return 0;
 }
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 7438c4affc75fa..b90f8692074397 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1801,13 +1801,12 @@ int free_swap_and_cache(swp_entry_t entry)
  *
  * This is needed for the suspend to disk (aka swsusp).
  */
-int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p)
+int swap_type_of(dev_t device, sector_t offset)
 {
-	struct block_device *bdev = NULL;
 	int type;
 
-	if (device)
-		bdev = bdget(device);
+	if (!device)
+		return -1;
 
 	spin_lock(&swap_lock);
 	for (type = 0; type < nr_swapfiles; type++) {
@@ -1816,30 +1815,34 @@ int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p)
 		if (!(sis->flags & SWP_WRITEOK))
 			continue;
 
-		if (!bdev) {
-			if (bdev_p)
-				*bdev_p = bdgrab(sis->bdev);
-
-			spin_unlock(&swap_lock);
-			return type;
-		}
-		if (bdev == sis->bdev) {
+		if (device == sis->bdev->bd_dev) {
 			struct swap_extent *se = first_se(sis);
 
 			if (se->start_block == offset) {
-				if (bdev_p)
-					*bdev_p = bdgrab(sis->bdev);
-
 				spin_unlock(&swap_lock);
-				bdput(bdev);
 				return type;
 			}
 		}
 	}
 	spin_unlock(&swap_lock);
-	if (bdev)
-		bdput(bdev);
+	return -ENODEV;
+}
 
+int find_first_swap(dev_t *device)
+{
+	int type;
+
+	spin_lock(&swap_lock);
+	for (type = 0; type < nr_swapfiles; type++) {
+		struct swap_info_struct *sis = swap_info[type];
+
+		if (!(sis->flags & SWP_WRITEOK))
+			continue;
+		*device = sis->bdev->bd_dev;
+		spin_unlock(&swap_lock);
+		return type;
+	}
+	spin_unlock(&swap_lock);
 	return -ENODEV;
 }
 
-- 
2.28.0

[PATCH 13/14] PM: mm: cleanup swsusp_swap_check

[Christoph Hellwig]

Use blkdev_get_by_dev instead of bdget + blkdev_get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/power/swap.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 9d3ffbfe08dbf6..71385bedcc3a49 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -343,12 +343,10 @@ static int swsusp_swap_check(void)
 		return res;
 	root_swap = res;
 
-	hib_resume_bdev = bdget(swsusp_resume_device);
-	if (!hib_resume_bdev)
-		return -ENOMEM;
-	res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
-	if (res)
-		return res;
+	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
+			NULL);
+	if (IS_ERR(hib_resume_bdev))
+		return PTR_ERR(hib_resume_bdev);
 
 	res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 	if (res < 0)
-- 
2.28.0

[PATCH 14/14] block: mark blkdev_get static

[Christoph Hellwig]

There are no users outside the core block code left now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/block_dev.c         | 3 +--
 include/linux/blkdev.h | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 2898d69be6b3e4..6b9d19ffa5af7b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1616,7 +1616,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
  * RETURNS:
  * 0 on success, -errno on failure.
  */
-int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
+static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
 {
 	int ret, perm = 0;
 
@@ -1637,7 +1637,6 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
 	bdput(bdev);
 	return ret;
 }
-EXPORT_SYMBOL(blkdev_get);
 
 /**
  * blkdev_get_by_path - open a block device by name
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5bd96fbab9b4c8..14117995091224 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1975,7 +1975,6 @@ void blkdev_show(struct seq_file *seqf, off_t offset);
 #define BLKDEV_MAJOR_MAX	0
 #endif
 
-int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
 struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
 		void *holder);
 struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
-- 
2.28.0

Re: [PATCH 11/14] PM: rewrite is_hibernate_resume_dev to not require an inode

[Rafael J. Wysocki]

On Thu, Sep 17, 2020 at 7:24 PM Christoph Hellwig <hch@lst.de> wrote:
>
> Just check the dev_t to help simplifying the code.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  fs/block_dev.c          |  2 +-
>  include/linux/suspend.h |  4 ++--
>  kernel/power/user.c     | 12 ++++++------
>  3 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 1a9325f4315769..2898d69be6b3e4 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -1885,7 +1885,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
>         if (bdev_read_only(I_BDEV(bd_inode)))
>                 return -EPERM;
>
> -       if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode))
> +       if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
>                 return -ETXTBSY;
>
>         if (!iov_iter_count(from))
> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
> index cb9afad82a90c8..8af13ba60c7e45 100644
> --- a/include/linux/suspend.h
> +++ b/include/linux/suspend.h
> @@ -473,9 +473,9 @@ static inline int hibernate_quiet_exec(int (*func)(void *data), void *data) {
>  #endif /* CONFIG_HIBERNATION */
>
>  #ifdef CONFIG_HIBERNATION_SNAPSHOT_DEV
> -int is_hibernate_resume_dev(const struct inode *);
> +int is_hibernate_resume_dev(dev_t dev);
>  #else
> -static inline int is_hibernate_resume_dev(const struct inode *i) { return 0; }
> +static inline int is_hibernate_resume_dev(dev_t dev) { return 0; }
>  #endif
>
>  /* Hibernation and suspend events */
> diff --git a/kernel/power/user.c b/kernel/power/user.c
> index d5eedc2baa2a10..b5815685b944fe 100644
> --- a/kernel/power/user.c
> +++ b/kernel/power/user.c
> @@ -35,12 +35,12 @@ static struct snapshot_data {
>         bool ready;
>         bool platform_support;
>         bool free_bitmaps;
> -       struct inode *bd_inode;
> +       dev_t dev;
>  } snapshot_state;
>
> -int is_hibernate_resume_dev(const struct inode *bd_inode)
> +int is_hibernate_resume_dev(dev_t dev)
>  {
> -       return hibernation_available() && snapshot_state.bd_inode == bd_inode;
> +       return hibernation_available() && snapshot_state.dev == dev;
>  }
>
>  static int snapshot_open(struct inode *inode, struct file *filp)
> @@ -101,7 +101,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
>         data->frozen = false;
>         data->ready = false;
>         data->platform_support = false;
> -       data->bd_inode = NULL;
> +       data->dev = 0;
>
>   Unlock:
>         unlock_system_sleep();
> @@ -117,7 +117,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
>
>         swsusp_free();
>         data = filp->private_data;
> -       data->bd_inode = NULL;
> +       data->dev = 0;
>         free_all_swap_pages(data->swap);
>         if (data->frozen) {
>                 pm_restore_gfp_mask();
> @@ -245,7 +245,7 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
>         if (data->swap < 0)
>                 return -ENODEV;
>
> -       data->bd_inode = bdev->bd_inode;
> +       data->dev = bdev->bd_dev;
>         bdput(bdev);
>         return 0;
>  }
> --
> 2.28.0
>

Re: [PATCH 09/14] ocfs2: cleanup o2hb_region_dev_store

[Joseph Qi]

On 2020/9/18 00:57, Christoph Hellwig wrote:
> Use blkdev_get_by_dev instead of igrab (aka open coded bdgrab) +
> blkdev_get.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

> ---
>  fs/ocfs2/cluster/heartbeat.c | 28 ++++++++++------------------
>  1 file changed, 10 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
> index 89d13e0705fe7b..0179a73a3fa2c4 100644
> --- a/fs/ocfs2/cluster/heartbeat.c
> +++ b/fs/ocfs2/cluster/heartbeat.c
> @@ -1766,7 +1766,6 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
>  	int sectsize;
>  	char *p = (char *)page;
>  	struct fd f;
> -	struct inode *inode;
>  	ssize_t ret = -EINVAL;
>  	int live_threshold;
>  
> @@ -1793,20 +1792,16 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
>  	    reg->hr_block_bytes == 0)
>  		goto out2;
>  
> -	inode = igrab(f.file->f_mapping->host);
> -	if (inode == NULL)
> +	if (!S_ISBLK(f.file->f_mapping->host->i_mode))
>  		goto out2;
>  
> -	if (!S_ISBLK(inode->i_mode))
> -		goto out3;
> -
> -	reg->hr_bdev = I_BDEV(f.file->f_mapping->host);
> -	ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL);
> -	if (ret) {
> +	reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev,
> +					 FMODE_WRITE | FMODE_READ, NULL);
> +	if (IS_ERR(reg->hr_bdev)) {
> +		ret = PTR_ERR(reg->hr_bdev);
>  		reg->hr_bdev = NULL;
> -		goto out3;
> +		goto out2;
>  	}
> -	inode = NULL;
>  
>  	bdevname(reg->hr_bdev, reg->hr_dev_name);
>  
> @@ -1909,16 +1904,13 @@ static ssize_t o2hb_region_dev_store(struct config_item *item,
>  		       config_item_name(&reg->hr_item), reg->hr_dev_name);
>  
>  out3:
> -	iput(inode);
> +	if (ret < 0) {
> +		blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE);
> +		reg->hr_bdev = NULL;
> +	}
>  out2:
>  	fdput(f);
>  out:
> -	if (ret < 0) {
> -		if (reg->hr_bdev) {
> -			blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
> -			reg->hr_bdev = NULL;
> -		}
> -	}
>  	return ret;
>  }
>  
> 

Re: [PATCH 02/14] block: switch register_disk to use blkdev_get_by_dev

[Sergei Shtylyov]

Hello!

On 17.09.2020 19:57, Christoph Hellwig wrote:

> Use blkdev_get_by_dev instead of open coding it using bdget_disk +
> blkdev_get.

    I don't see where you are removing bdget_disk() call (situated just before
the below code?)...

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/genhd.c | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/block/genhd.c b/block/genhd.c
> index 7b56203c90a303..f778716fac6cde 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -732,10 +732,9 @@ static void register_disk(struct device *parent, struct gendisk *disk,
>   		goto exit;
>   
>   	set_bit(GD_NEED_PART_SCAN, &disk->state);
> -	err = blkdev_get(bdev, FMODE_READ, NULL);
> -	if (err < 0)
> -		goto exit;
> -	blkdev_put(bdev, FMODE_READ);
> +	bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
> +	if (!IS_ERR(bdev))
> +		blkdev_put(bdev, FMODE_READ);
>   
>   exit:
>   	/* announce disk after possible partitions are created */

MBR, Sergei

Re: [PATCH 13/14] PM: mm: cleanup swsusp_swap_check

[Rafael J. Wysocki]

On Thu, Sep 17, 2020 at 7:39 PM Christoph Hellwig <hch@lst.de> wrote:
>
> Use blkdev_get_by_dev instead of bdget + blkdev_get.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  kernel/power/swap.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 9d3ffbfe08dbf6..71385bedcc3a49 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -343,12 +343,10 @@ static int swsusp_swap_check(void)
>                 return res;
>         root_swap = res;
>
> -       hib_resume_bdev = bdget(swsusp_resume_device);
> -       if (!hib_resume_bdev)
> -               return -ENOMEM;
> -       res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
> -       if (res)
> -               return res;
> +       hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
> +                       NULL);
> +       if (IS_ERR(hib_resume_bdev))
> +               return PTR_ERR(hib_resume_bdev);
>
>         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
>         if (res < 0)
> --
> 2.28.0
>

Re: [PATCH 02/14] block: switch register_disk to use blkdev_get_by_dev

[Christoph Hellwig]

On Fri, Sep 18, 2020 at 11:52:39AM +0300, Sergei Shtylyov wrote:
> Hello!
>
> On 17.09.2020 19:57, Christoph Hellwig wrote:
>
>> Use blkdev_get_by_dev instead of open coding it using bdget_disk +
>> blkdev_get.
>
>    I don't see where you are removing bdget_disk() call (situated just before
> the below code?)...

Indeed.  That's what you get for a messy last minute rebase.. :(

Re: [PATCH 11/14] PM: rewrite is_hibernate_resume_dev to not require an inode

[Pavel Machek]

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On Thu 2020-09-17 18:57:17, Christoph Hellwig wrote:
> Just check the dev_t to help simplifying the code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH 13/14] PM: mm: cleanup swsusp_swap_check

[Pavel Machek]

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On Thu 2020-09-17 18:57:19, Christoph Hellwig wrote:
> Use blkdev_get_by_dev instead of bdget + blkdev_get.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH 01/14] block: move the NEED_PART_SCAN flag to struct gendisk

[Jan Kara]

On Thu 17-09-20 18:57:07, Christoph Hellwig wrote:
> We can only scan for partitions on the whole disk, so move the flag
> from struct block_device to struct gendisk.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Makes sense. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  block/genhd.c             | 4 ++--
>  drivers/block/nbd.c       | 8 ++++----
>  drivers/ide/ide-gd.c      | 2 +-
>  fs/block_dev.c            | 7 +++----
>  include/linux/blk_types.h | 4 +---
>  include/linux/genhd.h     | 2 ++
>  6 files changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/block/genhd.c b/block/genhd.c
> index 9d060e79eb31d8..7b56203c90a303 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -731,7 +731,7 @@ static void register_disk(struct device *parent, struct gendisk *disk,
>  	if (!bdev)
>  		goto exit;
>  
> -	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +	set_bit(GD_NEED_PART_SCAN, &disk->state);
>  	err = blkdev_get(bdev, FMODE_READ, NULL);
>  	if (err < 0)
>  		goto exit;
> @@ -2112,7 +2112,7 @@ bool bdev_check_media_change(struct block_device *bdev)
>  	if (__invalidate_device(bdev, true))
>  		pr_warn("VFS: busy inodes on changed media %s\n",
>  			bdev->bd_disk->disk_name);
> -	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +	set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
>  	return true;
>  }
>  EXPORT_SYMBOL(bdev_check_media_change);
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 15eed210feeff4..2dca0aab0a9a25 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -315,7 +315,7 @@ static void nbd_size_update(struct nbd_device *nbd)
>  			bd_set_nr_sectors(bdev, nr_sectors);
>  			set_blocksize(bdev, config->blksize);
>  		} else
> -			set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +			set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
>  		bdput(bdev);
>  	}
>  	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
> @@ -1322,7 +1322,7 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b
>  		return ret;
>  
>  	if (max_part)
> -		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +		set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
>  	mutex_unlock(&nbd->config_lock);
>  	ret = wait_event_interruptible(config->recv_wq,
>  					 atomic_read(&config->recv_threads) == 0);
> @@ -1500,9 +1500,9 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
>  		refcount_set(&nbd->config_refs, 1);
>  		refcount_inc(&nbd->refs);
>  		mutex_unlock(&nbd->config_lock);
> -		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
>  	} else if (nbd_disconnected(nbd->config)) {
> -		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
>  	}
>  out:
>  	mutex_unlock(&nbd_index_mutex);
> diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c
> index 661e2aa9c96784..e2b6c82586ce8b 100644
> --- a/drivers/ide/ide-gd.c
> +++ b/drivers/ide/ide-gd.c
> @@ -230,7 +230,7 @@ static int ide_gd_open(struct block_device *bdev, fmode_t mode)
>  				bdev->bd_disk->disk_name);
>  		drive->disk_ops->get_capacity(drive);
>  		set_capacity(disk, ide_gd_capacity(drive));
> -		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +		set_bit(GD_NEED_PART_SCAN, &disk->state);
>  	} else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) {
>  		ret = -EBUSY;
>  		goto out_put_idkp;
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 0b34955b9e360f..1a9325f4315769 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -910,7 +910,6 @@ struct block_device *bdget(dev_t dev)
>  		bdev->bd_super = NULL;
>  		bdev->bd_inode = inode;
>  		bdev->bd_part_count = 0;
> -		bdev->bd_flags = 0;
>  		inode->i_mode = S_IFBLK;
>  		inode->i_rdev = dev;
>  		inode->i_bdev = bdev;
> @@ -1385,7 +1384,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
>  
>  	lockdep_assert_held(&bdev->bd_mutex);
>  
> -	clear_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
> +	clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
>  
>  rescan:
>  	ret = blk_drop_partitions(bdev);
> @@ -1509,7 +1508,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
>  			 * The latter is necessary to prevent ghost
>  			 * partitions on a removed medium.
>  			 */
> -			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
> +			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
>  			    (!ret || ret == -ENOMEDIUM))
>  				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
>  
> @@ -1539,7 +1538,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
>  			if (bdev->bd_disk->fops->open)
>  				ret = bdev->bd_disk->fops->open(bdev, mode);
>  			/* the same as first opener case, read comment there */
> -			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
> +			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
>  			    (!ret || ret == -ENOMEDIUM))
>  				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
>  			if (ret)
> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 6ffa783e16335e..eb20e28184ab19 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -19,8 +19,6 @@ struct cgroup_subsys_state;
>  typedef void (bio_end_io_t) (struct bio *);
>  struct bio_crypt_ctx;
>  
> -#define BDEV_NEED_PART_SCAN		0
> -
>  struct block_device {
>  	dev_t			bd_dev;
>  	int			bd_openers;
> @@ -39,7 +37,7 @@ struct block_device {
>  	struct hd_struct *	bd_part;
>  	/* number of times partitions within this device have been opened. */
>  	unsigned		bd_part_count;
> -	unsigned long		bd_flags;
> +
>  	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */
>  	struct gendisk *	bd_disk;
>  	struct backing_dev_info *bd_bdi;
> diff --git a/include/linux/genhd.h b/include/linux/genhd.h
> index 1c97cf84f011a7..38f23d75701379 100644
> --- a/include/linux/genhd.h
> +++ b/include/linux/genhd.h
> @@ -191,6 +191,8 @@ struct gendisk {
>  	void *private_data;
>  
>  	int flags;
> +	unsigned long state;
> +#define GD_NEED_PART_SCAN		0
>  	struct rw_semaphore lookup_sem;
>  	struct kobject *slave_dir;
>  
> -- 
> 2.28.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 11/14] PM: rewrite is_hibernate_resume_dev to not require an inode

[Pavel Machek]

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On Mon 2020-09-21 09:19:55, Christoph Hellwig wrote:
> Just check the dev_t to help simplifying the code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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[PATCH 11/14] PM: rewrite is_hibernate_resume_dev to not require an inode

[Christoph Hellwig]

Just check the dev_t to help simplifying the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 fs/block_dev.c          |  2 +-
 include/linux/suspend.h |  4 ++--
 kernel/power/user.c     | 12 ++++++------
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1a9325f4315769..2898d69be6b3e4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1885,7 +1885,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (bdev_read_only(I_BDEV(bd_inode)))
 		return -EPERM;
 
-	if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode))
+	if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
 		return -ETXTBSY;
 
 	if (!iov_iter_count(from))
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index cb9afad82a90c8..8af13ba60c7e45 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -473,9 +473,9 @@ static inline int hibernate_quiet_exec(int (*func)(void *data), void *data) {
 #endif /* CONFIG_HIBERNATION */
 
 #ifdef CONFIG_HIBERNATION_SNAPSHOT_DEV
-int is_hibernate_resume_dev(const struct inode *);
+int is_hibernate_resume_dev(dev_t dev);
 #else
-static inline int is_hibernate_resume_dev(const struct inode *i) { return 0; }
+static inline int is_hibernate_resume_dev(dev_t dev) { return 0; }
 #endif
 
 /* Hibernation and suspend events */
diff --git a/kernel/power/user.c b/kernel/power/user.c
index d5eedc2baa2a10..b5815685b944fe 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -35,12 +35,12 @@ static struct snapshot_data {
 	bool ready;
 	bool platform_support;
 	bool free_bitmaps;
-	struct inode *bd_inode;
+	dev_t dev;
 } snapshot_state;
 
-int is_hibernate_resume_dev(const struct inode *bd_inode)
+int is_hibernate_resume_dev(dev_t dev)
 {
-	return hibernation_available() && snapshot_state.bd_inode == bd_inode;
+	return hibernation_available() && snapshot_state.dev == dev;
 }
 
 static int snapshot_open(struct inode *inode, struct file *filp)
@@ -101,7 +101,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	data->frozen = false;
 	data->ready = false;
 	data->platform_support = false;
-	data->bd_inode = NULL;
+	data->dev = 0;
 
  Unlock:
 	unlock_system_sleep();
@@ -117,7 +117,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 
 	swsusp_free();
 	data = filp->private_data;
-	data->bd_inode = NULL;
+	data->dev = 0;
 	free_all_swap_pages(data->swap);
 	if (data->frozen) {
 		pm_restore_gfp_mask();
@@ -245,7 +245,7 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 	if (data->swap < 0)
 		return -ENODEV;
 
-	data->bd_inode = bdev->bd_inode;
+	data->dev = bdev->bd_dev;
 	bdput(bdev);
 	return 0;
 }
-- 
2.28.0